Coupler devices with closure valves have long been known in the prior art. They are used particularly in situations where it needs to be prevented after a transfer that the transferred fluid spills out of the separated coupler parts.
A coupler device with closure valves is disclosed in U.S. Pat. No. 1,827,286 A. The subject is in this case a coupler unit for railroad cars and locomotives. Each of the coupler halves has a ball valve which can be individually actuated and which can be closed before separating the coupler halves, if necessary, so that after separating the coupler device, the gas pressure in the conduits can be maintained and the brakes will not be engaged.
The know state of the art further includes many bottle closures with a fold-down closure cap. A bottle closure of this type is disclosed for example in U.S. Pat. No. 5,484,070, which in addition includes a child safety device.
The bottle closures of the known state of the art are entirely unsuitable for a safe transfer of the aforementioned toxic substances, since no seal-tight connection can be achieved between the mouth of the closure and the working reservoir without first folding back the closure cap and exposing the opening of the bottle.
Couplers with closure cap and exposing the opening of the bottle.
Couplers with closure valves in both coupler parts are likewise not suited for the purpose, as there is a dead volume between the two valve where residues of the transferred substance remain caught and can get into the environment as soon as the coupler parts are separated.
It is therefore the object of the present invention to provide a transfer device for laboratory containers which allows in particular a substance in powder form to be transferred quickly and safely from a first container into a second container, wherein the transfer of the substance from the first into the second container occurs in essence under a tight seal, so that no substance particles can escape to the outside during and after the transfer operation, or that the gaseous medium in the container is prevented as much as possible from mixing with the ambient air.